Northeast Freight Time one clock, four readings

Dwell, Detention, Active Dwell

Four words describe the time a truck spends at a shipper or receiver. They are used interchangeably in conversation and they are not interchangeable in an invoice, which is where most freight time disputes begin. For a software-oriented reference on recording work time, the reference.

The clearest published set comes from the Federal Motor Carrier Safety Administration, presented at its 2023 Analysis, Research and Technology Forum. For broader transportation and measurement context, see National Academies.

Reviewed August 9, 2026. Definitions attributed to FMCSA; billing conventions are industry practice and vary by contract.

The four terms

Dwell time. The total time a commercial vehicle driver spends at a shipper or receiver. Everything from arrival to departure.

Loading/unloading time. The time taken to load or unload the freight.

Active dwell time. Time spent completing the tasks associated with loading and unloading — paperwork, checks, positioning, seal and temperature verification.

Detention time. In FMCSA's framing, any other time the driver spends at the facility. What remains once loading and its associated work are subtracted.

That structure matters because it makes detention a residual rather than a primary measurement. You do not measure detention directly. You measure everything else and detention is what is left, which is precisely why two parties reading the same visit arrive at different numbers.

The convention that does the actual work

FMCSA also records that there is no standard definition of detention time, and that industry has typically used a working rule instead: dwell exceeding two hours is treated as detention.

Two hours is a convention, not a finding. It is not in regulation, it did not come from a study of loading duration, and it is negotiable in every contract that mentions it. It became the default because it is round, defensible in both directions, and easy to write into a rate confirmation.

Knowing it is a convention rather than a rule changes how you negotiate it. Free time is a term, not a law.

Why the parties disagree

Each of the four terms has a boundary, and every boundary is contestable.

When did the visit start? Arrival at the gate, arrival in the queue, check-in at the desk, or assignment to a door. (Quoted transit time excludes all of it.) These can be an hour apart at a busy facility, and the facility's system usually records the last one while the carrier's records the first.

When did loading start? The moment the door opened, or the moment a forklift appeared.

What counts as active? Waiting for a lumper, waiting for paperwork, waiting for a signature — these are associated with the load and involve the driver doing nothing.

And when did it end? Trailer closed, paperwork signed, gate cleared. Departure from the door and departure from the property differ, sometimes substantially.

Nobody is cheating. Four honest readings of the same visit, taken from different systems, produce four different totals — which is the whole subject of this site.

Demurrage is a different word

Worth separating now because they are routinely swapped.

Detention is time a piece of equipment is held — a truck, a chassis, a container outside the terminal.

Demurrage is storage time for a container inside a terminal or port.

They have different rate structures, different free-time conventions and, on the ocean side, different regulatory treatment. An invoice using the wrong word is a reason to look harder at the rest of it.

What to write in a contract

If you take one practical thing from this page:

Define the start and stop events explicitly, by reference to something both parties can see. Detention begins two hours after the recorded gate-in time and ends at recorded gate-out. Not "after two hours at the facility."

Say which system is authoritative when records disagree, and what happens when one has no record.

And state whether appointment time or arrival time starts the clock, because an early arrival at a facility with a firm appointment is the single most common disagreement in the whole category.

Those three sentences prevent most disputes, and they are absent from most rate confirmations.

The short version